Just about the same time as @anon10067017 I wrote a similar suggestion in the gyroscope thread. As there seems to be some consensus that this might work (security-wise/technically, ergonomically, aesthetically), I couldn’t resist the urge to create a drawing 
Again, summary of the concept:
-
Camera is hidden by a slider as suggested by @uzanto
Slider optionally doubles as shutter-release button. Sliding itself might toggle camera power, implicitly notifying OS about camera status, launching camera app -
Kill switches for Microphone, WiFi/BT, Baseband
sliders visually represent their state, as shown in @koenaad’s example above
(bonus points if the red/green tones are made from anodized aluminum) -
Internal DIP switches for all the above (Cam, Mic, WiFi, BT, Baseband) plus all other sensors (GPS, Accelerometer, Gyroscope, Compass, Ambient Light, Proximity), really small DIPs
Why duplicate external switches? Because internal switches are never toggeled by accident, if people want to turn them off for good. Also, by turning off BT internally, the external Wifi/BT switch becomes a WiFi switch.
Why additional switches? Because even the gyroscope could spy on you… (*) Or to save energy on unused sensors.
(*) which also means, as a sane default, a web browser should not give access to any sensor data.
@nicole.faerber, @francois-techene, thanks for your kind consideration 